Within my circle of friends, there is a rumour going round that you should switch provider if you want to get the best service. If you are a normal customer, there is only a limited service budget available. Once you quit however, companies fight to win you and suddenly more money is available.
It is best to terminate your contract just before it expires. You will then get advice from a whole range of sales people, and they are well resourced. They can offer incentives and special offers. You will feel like a star.
For providers this sounds like a recurring nightmare. All the money will go on winning loyalty. Fortunately, my direct competitors have the same problem.
This is a good tactic for smart customers and a big source of stress for companies, who cannot win. Whoever decides budget allocations, should reconsider maintaining customers. And no, omni-channel is not the solution for this situation. It only alters the way you see the core of the problem. Customer alienation is a problem, both at the top and with the entire system.